Three-dimensional vertical NAND strings having one bit per cell are disclosed in an article by T. Endoh et al., titled “Novel Ultra High Density Memory With A Stacked-Surrounding Gate Transistor (S-SGT) Structured Cell”, IEDM Proc. (2001) 33-36. While NAND strings can be employed to provide a high density three-dimensional memory device, the operational speed of the NAND strings is slower than desired due to inherent delays that are present during programming and sensing.